Automatic motor-reverser.



No. 21,009. PATENTED MAY 22, 1906.

G. H. WHITTINGHAM.

AUTOMATIC MOTOR REVERSER.

APPLICATION FILED DEC; 9, 1902. RENEWED OCT. 21, 1905.

3 SHEETS-SHEET l No. 821,009. PATENTED MAY 22, 1906'. G. H. WHITTINGHAM.

AUTOMATIC MOTOR REVERSER.

APPLICATION FILED DEG,9,1902. RENEWED 00T.21,1905.

s SHEETS-SHEET 2.

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Hwuzoeo I 5 z W 814001110? W 1J EIH'OT/HQU W No. 821,009. PATENTBD MAY 22, 1906.

-G. H. WHITTINGHAM. AUTOMATIC MOTOR REVERSER.

APPLICATION FILED DEC. 9. 1902. RENEWED 0GT.-21, 1905.

3 SHEETSSHEET 3.

q/piimeooco Wfinvanl'ot UNITED {STATES PATENT OFFICE.

GEORGE Hi WHITTINGHAM, NEW YORK, N. Y., ASSIGNOR TO AUTO- MATIC SWITCH COMPANY, A CORPORATION OF MARYLAND.

AUTOMATIC Mo'r'oa REvE 'sER.

ratentea May 22, 1906.

Application filed December 9, 1902. Renewed October 21, 1905. Serial No. 283,804.

To all whom it may concern:

Be it known that I, GEORGE H. WHITTING- HAM, a citizen of-the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Automatic Motor-Reversers, of which the following is a full, clear, and exact specification.

This invention relates -to automatic motor-reversing apparatus; and its object is to provide an apparatus of this character wherein when t e motor is reversed itis absolutely protected against the introduction.

of current until after 1t has first been stopped and is in condition to safely receive current to drive it in the opposite direction. Heretofore it has been attem ted to accomplish this by mechanically latc liing the controllerarm at determined times, but such devices have been to some extent within the control of the operator.

So far as I am aware I am the first to provide means for accomplishing the foregoing objects automatically inde endently. of the operator and by means w olly beyond his control.

The invention comprises various features of advantage, which will be described more in detail hereinafter.

Referring more particularly to the drawings, Figure 1 is a diagram of an ap a'ratus embodying m connections w e the motor is running in one direction. Fig. 2 illustrates the connections immediatelyafter the controlling-arm is moved to the reverse position, and Fig. 3 illustrates the connection while the motor is running in the opposite direction.

A re resents t e armature of the motor, and B t e field.

C represents an automatic motor-starter of any convenient type adapted to automatically cut out resistance from the armature-circuit when said circuit is made and to insert said resistance when the circuit is.

broken.

1 and 2 represent the terminals of the circuit from which the motor is to be driven.

The field-circuit of'the motor is through the blade 3 to the contact 4 and wire 5 to field B, thence through wire-6 to and through coil 7 and wires 8 and 9 to terminal 2. The armature-circuit when the motor is runnin in the direction of Fig. 1 is from wire 5 t ough invention, illustratlng the,

' wire 10 to blade 11 and contact 12 and through wires 13 and 14 to the automatic starter O, thence wire 15 to armature A, and thence by wires 16 and 17 to contact 18 and blade 19 and wires 20 and 9 to terminal 2.

When the blades 11 and 19 are moved into engagement with the o osite contacts 21 and 22, a circuit is estab ishedthrough the armature in the opposite direction, as follows: terminal 1, blade 3, contact 4, wires 5 and 10, blade 11, contact 21, Wires 23 and 16, armature A, wire 15, automatic starter. O, Wires 14 and 24, contact 22, blade 19, wires 20 and 9 to terminal 2.

The blades 11 and 19 of the reversingswitch D are mounted upon a common sulp- Eort 25, adapted to be moved to bring t e lades 11 and 19 into contact with contacts 12 and 18, respectively, or with contacts 21 and 22, respectively. The movement of the support is controlled in this instance by 0 positel -acting solenoids, the cores of whic 26 .an 27, are attached to the respective sides of the sup ort 25. The coils 28 and 29 of the solenoi s are arranged to act in o posite directions and connected across t e inc in series with each other. The circuit is as follows: terminal '1, wire 30, coils 28 and 29, wire 31, wire 9 to terminal 2. The cores 26 and 27 are so adjusted that when one core is drawn into its surroundin coil the other pole will be more or less with rawn from the influence of its coil. Therefore when coils 28 and 29 are energized theblades 11 and 19 are moved to make contact with the contacts on one side they will be held' there owing to the coil, on that side having the greater influence upon its core.

The blades 32 and 33 of the operating-controller E are adapted, respectively, to con- 7 nect the contacts 34 and 35 or 36'and 37 and 38 and 39 or 40 and 41. A wire 42 leads to the coil 43, and coil 43 is connected by Wire 44 with contacts 35 and 36. Coil 43 controls the core'45, which is connected to blade 3, thus closing blade 3 upon contact 4 when coil 43 is energized. The contacts 34' and 37 are respectively connectedgby the wires 46 and 47 with the contacts 48 and 49, one of which blades is engaged by the blade 19, according to whether the blade is at one side or the other. A circuit through the coil 43'wi1l therefore be provided in either position of the support 25 and its blades. Whenin the position .shown in Fig. 1, the circuit is as follows: terminal 1, wire 42, coil' 43, wire 44, contact 36, blade 32, contact 37, wire 47, contact 49, blade 19, wires 20 and 9 to terminal 2. When the controller E and support and contact-blades are moved into the position shown in Fig. 3, the circuit is as follows: terminal 1, wire 42, coil 43, wire 44, contact 35, blade 32, contact 34, wire 46, contact 48, blade 19, wires 20 and 9 to terminal 1.

The support 25, carrying the contactblades 11 and 19, is moved by short-circuiting one of the coils 28 or 29 and permitting the other coil to move the blades. When blade 33 of the controller E connects contacts 38 and 39, coil 29 is short-circuited, thus: from wire to contact 38, blade 33 to contact 39, wire 51 to contact 52, contact-bar 53, contact 54, wire to coil-29 and wire 31. When blade 33 connects contacts 40 and 41, coil 28 is short-circuited, thus: wire 55, contact 54, blade 53, contact 52, wire'51, contact 40, blade 33, contact 41, wire 56, wire 30, coil 28.

Contact-bar 53 is carried by the core 57, which is surrounded by coil 7, and therefore as long as coil 7 is energized blade 53 will be held out of engagement with its contacts, and thus neither of the above short circuits can be established while current is passing through coil 7.

The operation is as follows: The circuit through coil 43 being closed, the coil holds blade 3 against contact 4, and thus closes the circuits through the field and through the motor, as before described; but as long as cur rent ispassing through the field of the motor, which -1s in series with coil 7, coil 7 will hold blade 53 away from contacts 52 and 54 and neither of the coils 28 or 29 can be short-circuited, no matter what the position of controller E. Coil 28 will therefore continue to hold the blades 1 1 and '19 in engagement with their contacts. When controller E is moved to the opposite position, as shown in Fig. 2, its first effect is to break the circuit through magnet 43, and thus release blade 3, where upon the main circuit through the field and through the armature is broken, as illustrated in Fig. 2. As the field-coil B is connected in shunt to the armature whether the reversing-switch is in one position or the other, then when the main circuit is opened at 4 the armature continuing to rotate will supply current to the field-circuit which includes coil 7. Thus bar 53 will be held away from contacts 52 54. Therefore as long as this condition continues the coil29 cannot be short-circuited and the reversing-switch D must remain in its original position. This condition of the circuits continues as long as there is any current of appreciable strength in the armature and field circuit. When the current dies out of the field-winding, due to the armature coming to rest,the coil 7 will be deenergized and core 57 will drop, causing blade 53 to connect contacts 52 and 54, whereupon coil 28 is short-circuited, as before described. 'lhcreupon. coil 29, which receives double current whenthe other coil is short-circuited, becomes operative to move the support 25, carrying blades 11 and 19, so that blades 11 and 19 contact, respectively, with contacts 21 and 48 and 22, as shown in. Fig. 3. When blade 19 contacts with contact 48, the circuit through coil 43 is again established and'coil 43 again closes the motorcircuit through the field and armature through blade 3. Thereupon the motor is started through the automatic starter C but the current entering the armature in the opposite direction causes the motor to operate accordingly. It will be noted that at the time the current is first introduced to the motor in the opposite direction there is no current in the motor, and the throwing of the reversing-switch will therefore not be at tended by objectionable sparking. As soon as the field is energized coil 7 again breaks the circuit through contacts 52 and 54 and prevents either of the coils 28 and 29 from being short-cireuited.

In order to insure that when the armaturecircuit of the motor is opened a short circuit through the motor-armature and abraking resistance shall be established and the connection thereof maintained while necessary and at the same time shall prevent the main armature-circuit from being reestablished until the current in short circuit is below a determined value, I provide the extension 58 upon blade 3, the extension carrying the contact-bar 59, insulated from theblade, but ada ted to connect contacts 60 61 when bla e 3 is out of contact with contact 4. Contact 60 is connected with one terminal of armature A by wire 62, which includes the braking resistance 63, and contact 61 is connectedwith the other terminal of the armature by wire 64, which includes coil 66. Coil 66 surrounds core 65, which is attached to eX- tension 58, and thus when coil 66 is energized it holds the bar 59 in engagement with contacts 60 and 61. Whenever magnet 43 re leases blade 3 and the s ring draws it back and closes the circuit t rough bar 59, the short circuit through the motor-armature and braking resistance is established, and the reactance-current in this circuit energizes coil 66, and thus not only revents the bar 59 from chattering against its contacts, but also prevents the circuit from being broken as long as the reactance-current isso large as to cause sparking upon the breaking of its circuit. As soon as the reactance-current dies out the coil 66 becomes powerl ss anc permits blade 3 to be moved. The strength of coil 66 will of course be adjusted according to individual conditions.

It will be noted that in the apparatus of the operator to operate the motor in any other manner than that determined upon.

Current cannot be introduced to the motor to start it in the opposite direction until the field is entirely free of current, which condition can only exist when the motor has come to a complete sto Furthermore, the switch will remain in the position set to run the motor in one direction and will not break the circuit except where a reversal of the motor is intentional. Thus the motor may be started again in the same direction without disturbing the connections of the reversingswitch. I J

It will be understood, of course, that the construction above described may be modified in various respects without de arting from the invention, and I therefore esire it to be understood that I do not limit myself herein to the specific construction herein shown. 1 Y

Obviously the connections may be arranged so that the current in the field-circuit is reversed instead of that in the armaturecircuit.

Having thus described my invention, 1 declare that what I claim as new, and desire to secure by Letters Patent, is

1. The combination with the armature and fieldwindings ofa motor, of means for preventmg a reversal of current in one of said wlndmgs except when the current in the other winding is less than a determined value.

2. The combination with a motor, of means for reversing the current in the armaturewindmg and means controlled by the strength of current in the field-winding for preventing such reversal except when the current in the field-winding is less than a determined value.

3. The combination of a motorand a re versmg-switch, means for setting the same, and means for maintaining the same in set positlon except when the current in the armature-winding is less than a determined value.

4. The combination with a motor, and a reversing-switch, oppositelyacting coils for operating the same, means for short-circuiting either of said coils, and means for preventing such short-circuiting except when the current in one of the motor-windings is below a determined value.

5. The combination with a motor, of a reversing-switch, oppositely-acting coils for operating the same,means for short-circuiting either of said coils when the current in one of the motor-windings is below a determined value, and means whereby upon making said short circuit current is introduced to "the motor.

6. The combination with a motor, of a reversing-switch, and oppositely-acting electromagnets for operating the same, said electromagnets being adapted to normally hold said switch in either one of its running positions, and means for reventing the switch from o erating until't e speed of the motor falls be ow a determined rate.

7. The combination with a motor, of a reversing-switch, two oppositely-acting forces for moving the switch to either one of two positions, and meanswhereby said forces normally hold said switch in either of said positions when moved thereto, and means for preventing the switch from operating until the s eed of the motor falls below a determined rate.

8. The combination with a motor, of a reversing-switch, armatures connected to the opposite sides of said switch, and two oppositely-acting coils respectively surrounding said armatures, said coils and armatures being so disaposed that when the switch is moved to one si e the equilibrium of the coils will be unbalanced.

9. The combination with a motor, of a reversing-switch, and two oppositely-acting electromagnets for o crating said switch, the equilibrium of said e ectromagnets being unstable, and means for changing said e uilib' rium when the speed of the motor falls elow a determined rate;

10. The combination with a motor, of areversing-switch, two oppositely-acting electromagnets for operating said switch, the equilibrium of said electromagnets being unstable, and means for changin said equilibrium when the current in one o the motorwindings is less than a determined value.

. 11. The combination with a motor, of a reversing-switch, two oppositely-aotin electromagnets for o crating said switc the equilibrium of sai electromagnets beingunstable, and means for Ipreventlng a change of equilibrium except w en the current in one of the motor-windings is less than a determined value.

' 12. The combination with a motor, of field and armaturewindings therefor, a reversing-switch in the armature-circuit, and means for preventing the throwing of thereversin -switch except when the current in the fie d-winding is less than a determined value, substantially as described.

13. The combination with a motor, of field and armature windings therefor, a re-' versing-switch in the armature-circuit, a controller adapted to establish circuits which shall become operative upon the throwing of the reversingswitch, and means whereby after said controller is operated the reversing-switch will be automatically thrown when the current in one of the motor-windings is less than a determined value, substantially as described.

' 14. The combination with a motor, of field and armature circuits therefor, a reversing-switch, a circuit-closing'switch adapted to establish the field and armature circuits upon the operation of the reversing-switch,

'ing the main circuit and for operating the remeans for establishing a short circuit through the armature-circuit and a braking resistance when said circuit-closing switch is opened, and means for maintaining said short circuit until the current therein is less than a determined value.

15. The combination with a motor of a circuit-closing switch therefor, means for establishing a short circuit through the motorarmature and a braking resistance upon the opening of said circuit-closer, and means for maintaining said circuit as long as the current therein is above a determined value substantially as described.

16. The combination with a motor, of a reversing-switch, a controlling-switch for openversing-switch and automatic means for pre- Venting the operation of the reversingswitch until the speed of the motor has fallen below a determined rate.

17. The combination with a motor, of a reversing-switch, and automatic means for controlling the latter, said means being allowed to operate the reversing-switch only when the speed of the motor has fallen below a determined rate.

In testimony whereof I aflix my signature in presence of two witnesses.

GEORGE H. WHITTINGHAM.

Witnesses:

HENRY BEST, JULIAN S. WOOSTER. 

